Answer:
Percentage lithium by mass in Lithium carbonate sample = 19.0%
Explanation:
Atomic mass of lithium = 7.0 g; atomic mass of Chlorine = 35.5 g; atomic mass of carbon = 12.0 g; atomic mass of oxygen = 16.0 g
Molar mass of lithium chloride, LiCl = 7 + 35.5 = 42.5 g
Percentage by mass of lithium in LiCl = (7/42.5) * 100% = 16.4 % aproximately 16%
Molar mass of lithium carbonate, Li₂CO₃ = 7 * 2 + 12 + 16 * 3 =74.0 g
Percentage by mass of lithium in Li₂CO₃ = (14/74) * 100% = 18.9 % approximately 19%
Mass of Lithium carbonate sample = 2 * 42.5 = 85.0 g
mass of lithium in 85.0 g Li₂CO₃ = 19% * 85.0 g = 16.15 g
Percentage by mass of lithium in 85.0 g Li₂CO₃ = (16.15/85.0) * 100 % = 19.0%
Percentage lithium by mass in Lithium carbonate sample = 19.0%
The two ways to measure the sand in a sand castle are by counting the number of pails of sand used to build the castle and by determining the mass of the sand used in building the castle. The first method makes use of the volume of the pail to determine the amount of sand while the second method is a more quantitative way.<span />
Answer:
Fe2O3 + __3_H2O --> __2_Fe(OH)3
Explanation:
____Fe2O3 + __3_H2O --> __2_Fe(OH)3
Fe -2 Fe -2
H - 6 H - 6
O - 6 O- 6
Explanation:
For an isothermal process equation will be as follows.
W = nRT ln
It is given that mass is 10 kg/s or 10,000 g/s (as 1 kg = 1000 g). So, calculate number of moles of water as follows.
No. of moles = 
= 
= 555.55 mol/s
= 556 mol/s (approx)
As T = 
or (50 + 273.15) K = 323.15 K. Hence, putting the given values into the above formula as follows.
W = nRT ln[/tex]\frac{P_{1}}{P_{2}}[/tex]
= 
= 
= -3440193.809 J/s
Negative sign shows work is done by the pump. Since, 1 J = 0.001 kJ. Therefore, converting the calculated value into kJ as follows.
= 3440.193 kJ/s
= 3451 kJ/s (approx)
Thus, we can conclude that the pump work is 3451 kJ/s.
Answer:
Sulfur — S
calcium — Ca
carbon — C
silver — Ag
gold — Au
helium — He
hydrogen — H
should become easier for you to memorise them as you go on in life (meaning going up a grade… grade 7 to 8 to 9 to 10 until you reach college and whatnot)
